Summary: For this lesson students will have background information from the previous class about what minerals are and how they are associated with rocks. will be a classification lab in which the students will be given known samples of minerals and they he students will learn about how unknown mineral samples are classified in the field of science. They will learn about the Mohs hardness scale and how to make comparisons to it. They review and use the identifiable characteristics of minerals, such as luster and color, which can be used to identify unknowns. The students will collect characteristics from observation. Then they will be given 5 unknown samples of rock which they will be identifying with the use of the information they learned about identifiable characteristics.
Objectives:
Students will collect data on known minerals.
Students will be able to identify unknown samples using the information learned about mineral classification.
Students will understand the Mohs hardness scale.
Students will be able to compare unknowns to the Mohs hardness scale.
Students will understand the characteristics such as luster, cleavage, fracture, color, transparency, and magnetism which are used to identify minerals.
Students will be able to explain the difference between cleavage and fracture.
Materials:
examples of different minerals
magnets
scratch plate
penny
glass plate
iron nail
steel file
List of 12 minerals and their characteristics
Instruction:
Opening:
I will open the lesson with a picture of fool's gold and a picture of real gold. I will ask the students which object they think is real gold in the picture?
Then I will ask them, how should we go about figuring which rock is gold ? Would we use similar method to identify the stone that is not gold?
As the students are stating ways that we could investigate how to decipher between the stones I would write their ideas on the board and give them feedback about their ideas.
Then I would tell the students that scientists that work with minerals and rocks, like geologists, have a set way to identify unknowns and today we are going to use those methods solve the gold mystery.
timing = 5 minutes
Middle:
To explain the Moh's hardness scale I will use an example. I would take a penny and a thick piece of pencil lead and I would ask the students which object they think would cause the other to become scratched.
After they answered, I would then explain to the students that these two objects have a known hardness and can be used with other objects to test the hardness of unknowns.
I would explain to the students that there is a chart called the Mohs hardness scale that catagorizes the hardness of certain minerals from 1 to 10. With talc being 1 and diamonds being 10.
I would then pass out a copy of this scale to the students so they can visually see the scale as I describe it.(scale image below)
Tell the students that there are other common objects that can be used to determine the relative scale number, on the Mohs hardness scale, of an unknown. Refer them to the Mohs scale of hardness and ask them to describe the hardness of each common item to make sure they all understand how to read the scale.
If they don't understand how to read the scale use questioning to probe for answers.
For review, ask the students to explain the physical characteristics of minerals they learned about last class; which include luster, cleavage and fracture, color, transparency, streak color, and magnetism.
Make sure to remind the students that any mineral above the hardness of 6.5 will dig into the streak plate and a white powder form the streak plate will result and that transparent and that many transparent mineral leave a white streak that is not help full for identifying purposes.
Explain that the procedure will include these steps.
Break into groups of 4-5
Choose 4 unknowns from the available unknowns and obtain one of the "gold" samples.
Write down a description of each of the unknowns based on observations and comparisons with the Mohs hardness scale. Make sure to include the number of the unknown with the description and a space to eventually write the mineral name .
Compare your descriptions with the list of minerals and their physical properties.
Decide which minerals fit the descriptions which you created for your unknowns and write down the name of the mineral on the same piece of paper as you descriptions of your unknowns.
timing = 30 - 35 minutes
Closing
I will instruct the students to return all of the materials and clean their desks and turn in their descriptions and answers for grading.
I will start a discussion about the unknowns and which ones were difficult to determine.
If there were unknowns difficult to determine I would have a group of students who determined the correct answer explain why it was correct to the class with information that they collected about the mineral.
I will make connections to the rock cycle by explaining how rocks are hardened forms of minerals.
For Homework I will have the students bring in a rock sample from their neighborhood or area.
Title: Mineral Identification
Summary: For this lesson students will have background information from the previous class about what minerals are and how they are associated with rocks. will be a classification lab in which the students will be given known samples of minerals and they he students will learn about how unknown mineral samples are classified in the field of science. They will learn about the Mohs hardness scale and how to make comparisons to it. They review and use the identifiable characteristics of minerals, such as luster and color, which can be used to identify unknowns. The students will collect characteristics from observation. Then they will be given 5 unknown samples of rock which they will be identifying with the use of the information they learned about identifiable characteristics.
Objectives:
Materials:
Instruction:
Opening:
- Then I will ask them, how should we go about figuring which rock is gold ? Would we use similar method to identify the stone that is not gold?
- As the students are stating ways that we could investigate how to decipher between the stones I would write their ideas on the board and give them feedback about their ideas.
- Then I would tell the students that scientists that work with minerals and rocks, like geologists, have a set way to identify unknowns and today we are going to use those methods solve the gold mystery.
- timing = 5 minutes
Middle:
- Tell the students that there are other common objects that can be used to determine the relative scale number, on the Mohs hardness scale, of an unknown. Refer them to the Mohs scale of hardness and ask them to describe the hardness of each common item to make sure they all understand how to read the scale.
- If they don't understand how to read the scale use questioning to probe for answers.
- For review, ask the students to explain the physical characteristics of minerals they learned about last class; which include luster, cleavage and fracture, color, transparency, streak color, and magnetism.
- Make sure to remind the students that any mineral above the hardness of 6.5 will dig into the streak plate and a white powder form the streak plate will result and that transparent and that many transparent mineral leave a white streak that is not help full for identifying purposes.
- Explain that the procedure will include these steps.
- Break into groups of 4-5
- Choose 4 unknowns from the available unknowns and obtain one of the "gold" samples.
- Write down a description of each of the unknowns based on observations and comparisons with the Mohs hardness scale. Make sure to include the number of the unknown with the description and a space to eventually write the mineral name .
- Compare your descriptions with the list of minerals and their physical properties.
- Decide which minerals fit the descriptions which you created for your unknowns and write down the name of the mineral on the same piece of paper as you descriptions of your unknowns.
- timing = 30 - 35 minutes
Closing- I will instruct the students to return all of the materials and clean their desks and turn in their descriptions and answers for grading.
- I will start a discussion about the unknowns and which ones were difficult to determine.
- If there were unknowns difficult to determine I would have a group of students who determined the correct answer explain why it was correct to the class with information that they collected about the mineral.
- I will make connections to the rock cycle by explaining how rocks are hardened forms of minerals.
- For Homework I will have the students bring in a rock sample from their neighborhood or area.
- timing 10-15 minutes
Notes- pictures of gold, http://blog.deborahblum.com/?cat=18
- picture of pyrite is from, http://breakfree2energy.blogspot.com/2010/06/pyrite.html
- picture of Mohs hardness scale is from, http://geology.csupomona.edu/alert/mineral/mohs.gif
accommodation: